[Mailman-Users] User flagged as no-mail with "?" for reason

[David Gibbs]

Folks:

Anyone know what could cause a user to be flagged as no-mail with a
reason code of "?"?

I can't find any indication that mail was bouncing, and I certainly
didn't set them no-mail myself.

This subscriber had been receiving mail fine up to a few days ago and
then it stopped ... they called me about it, and when I looked, they
were flagged no mail.

Any thoughts?

Thanks!

david